1. Field of the Invention
This invention relates generally to the commercial refrigeration art, and more particularly to improvements in structural frame assemblies for food product merchandisers.
2. Description of Prior Art
Great advances have been made in the last forty years in the field of commercial food merchandising with improved insulation materials, better refrigerants, more efficient air handlers and condensing unit systems, better lighting and the universal use of ambient air temperature and humidity control in food stores and the like. A long checklist of important factors influence the construction and manufacture of food merchandisers including refrigeration requirements and performance, structural engineering for strength, durability and safety as well as insulation effect, servicing capability, product merchandising potential, and both manufacturing and operating costs.
In today's marketplace a wide variety of food merchandisers are used to best market different types of food products as well as meet their cooling needs. In the low temperature field, frozen food merchandisers maintain product display temperatures at about 0.degree. F. and ice cream cases operate at about -5.degree. F. to '10.degree. F. Frozen foods are best protected in reach-in coolers (with glass front doors), but open front, multi-deck merchandisers best display various food products. Similarly, in the medium temperature field of 28.degree. F. to 50.degree. F. product temperature range, glass front deli merchandisers are generally preferred for the marketing of freshly cut meats, cheeses, prepared salads and other deli items, but open front multi-deck merchandisers are widely used for packaged meat and dairy products and single deck cases are preferred for fresh produce. Even with some industry standardization at eight (8') foot and twelve (12') foot lengths for merchandisers, the manufacture of each commercial refrigerator fixture has remained a hand built operation.
Each type of commercial refrigerated merchandiser in the past largely has been individually designed for a specific food display or storage purpose, and fabrication generally has been a custom assembly process. These prior art merchandisers have had bulky internal frame assemblies with normally heavy insulation positioned to span between the frame members and form an integral part of the inner cabinet cooling system. Commercial merchandisers conventionally use evaporator coils of the fin and tube type, which in the past have extended the full length of the merchandiser as was thought necessary to best achieve even, balanced air flow distribution for uniform air cooling from end-to-end throughout the length of the display area. It has been discovered that modular external support frame structures can effectively support most commercial merchandiser cabinets--whether single deck as in deli and produce types, or 2-5 multi-deck cases for frozen foods, fresh meats or dairy products. The modularity of such external frame structures of the present invention is accommodated by the use of shortened vertical length internal struts that only need to support the weight of insulated panels and duct forming members, and which, in turn, can accommodate a novel modular evaporator coil concept as disclosed more fully in a commonly assigned patent application of John A. Behr entitled Refrigerated Merchandiser With Modular Evaporator Coils and EEPR Control, co-pending herewith. The supporting frame structure of the present invention will accommodate conventional full length evaporator coil construction and placement as well as the newer modular coil concepts.